The image reading apparatus conveys a reading unit or a document to read the document. Conveyance is implemented by motor control based on a target position trajectory. The reading unit reads the document each time a line start signal is inputted. When a predetermined condition is satisfied, the reading operation is invalidated. A conveyance position at a timing to start the first reading operation invalidated is specified as an interrupted position. The object is arranged at a conveyance restart position moved back from the interrupted position. A target position trajectory is newly set. A conveyance time from the conveyance restart position to the interrupted position defined by the target position trajectory is an integral multiple of an output cycle of the line start signal. The motor control based on the target position trajectory is started at a timing coinciding with an output timing of the line start signal.